Hopper for stokers



0d. 3, 1933. Q CARTER 1,928,962

HOPPER FOR STOKERS Filed DeC. 26, 1929 }"\.C. CARTER Patented Oct. 3, 1933 UNITED STATES PATENT OFFICE Haskell C. Carter, Portland, Oreg., assignor to Iron Fireman Manufacturing Company, Portland, Oreg.

Application December' 26, 1929 Serial No. 416,580

3 Claims.

This invention relates generally to coal burnlng stokers of the forced draft under-fired type, and particularly to a special form of hopper used in conjunction withvsuch devices.

The main object of this invention is to provide a hopper which can be hermetically sealed at its inlet.

The second object is to produce a closed hopper,

'the shape'of whose closed end will not only conform to the interior slope of coal when heaped in the hopper, but will also give the maximum amount of clearance for the fire door of the furnace and expedite the filling of the hopper.

The thirdobject is to provide a body for the hopper which can be introduced between the top and the hopper base and secured in position by means of flanged air tight joints for the purpose of permitting'the use of various sizes of hopper body without changing the hopper base or top, thereby making it possible to have a large range of hopper capacities.

The fourth object is to construct a cover or lid for the filling hole in the hopper top having a three point fastening, two of which consist of hinges and the third a spring-urged lock which normally urges the cover to an air tight position, and also serves as a safe guard in event there should be a back fire of gas which would cause a rise of pressure within the hopper.

The fifth object is to provide a special form of gasket for the hopper cover which can be brought to a full seat with a small amount of pressure.

These, and other objects, will become more apparent from the specification following as illustrated in the accompanying drawing, in which:

Figure 1 is a longitudinal section through the hopper and a portion of the furnace.

Figure 2 is an end elevation of the stoker of which the hopper forms a part.

Figure 3 is a vertical section through the cover fastening device taken along the linel3-3 in Figure 2.

Figure 4 is a perspective view of a representative hopper body section.

Similar numbers of reference refer to similar parts throughout the several views.

Referring in detail to the drawing, in order to illustrate this invention there is shown the front 50 walls 10 of a furnace, as well as the usual fire door 11. The ash pit door has been removed and through its opening has been placed a fuel feed duct 12 through which coal is fed upwardly to the tuyres 13 'by means of a feed screw 14. Air is 55 fed to the combustion by means of a fan 15 '19, back 20 and sides 21.

whose air duct (not shown) also passes through the ash door opening which is otherwise closed by means of the'refractory seal 16. The hopper base 17 has its upper edge 18 flanged upon which is mounted the hopper body consisting of a front The lower edge 22 of the hopper body is outwardly flanged to conform to the edge 18 of the hopper base 17. The upper edge 23 of the hopper body is inturned.

In some instances it is desirable to provide an agitator to prevent the coal from arching in the hopper. In this instance it consists of a spiral worm shaft 24 which journals in the hopper base 17 and is driven from the reduction gearing contained within the casing 25 from which is also 70 driven the fuel feed screw 14.

On the inturned edge 23 of the hopper body is mounted the top of the hopper which consists of a somewhat roof 4shaped structure having a sloping front 26 which contains an opening 27 for 75 the introduction of fuel. Joined to the top of the front 26 and sloping in the opposite direction is the back 28. The sides 29 extend between the front 26 and the back 28. The cover 30 for the opening 27 is provided with a pair of hinges 31 at the upper side of the opening 27. The cover 30 is provided with a flanged edge 32 adapted to surround the opening 27. Between the cover 30 and the rim 33 of the opening 27 is placed a gasket 34 which, owing to its shape, is quite resilient and permits the formation of a perfect seal for the cover 30 with only a slight amount of pressure on thei outside of the cover 30. Ordinarily additional pressure developed within the hopper would merely tend to improve the seal. In order to hold the cover 30 to a sealed position there is provided a latch 35 adapted to engage the under side 'of the cover 30. The latch 35 is mounted on a rod 36 which is slidable and rotatable with. in the sleeve 37 which, in turn, is secured to the cover 30. On the outwardly projecting portion of the rod 36 is placed a spring 38 and on the end of the rod 36 is secured a latch operating handle 39.

With this construction it is a simple and easy matter to latch the cover 30 into a hopper closing position in which gas or dust cannot escape from the hopper. If, however, for any reason gas did explode within the fuel duct 12 or the hop- 105 per itself there will be no breakage of any kind, the cover 30 merely yielding against the spring 38 until the excess of pressure has been relieved.

It is of course desirable to provide suitable packing between the flanged. ends 22 and 23 and no their associated parts to which they are attached by means of the bolts 40.

It can thus be seen that while the structure above described is of good appearance it is also extremely useful for the purpose intended. It can be seen in Figure 1 that it is a simple matter to introduce fuel into the hopper by means of a coal hod 41, or by `means of a shovel without danger of having any of it find its Way on the floor of the furnace room. In other Words, it is possible to heap the hopper to a greater degree than can be accomplished Without a cover, the net result being an increase in capacity Without an apparent increase in size.

In View of the fact that these devices are employed under a wide range of operating conditions, including the rate of coal burned, the kind of coal burned, draft and other factors, it can be seen that what would be a suitable size of hopper in one installation would be entirely unsatisfactory in another; in fact, a great many sizes are required to take care of the trade requirements. By the arrangement above described it is only necessary to change one element in the hopper, namely that illustrated in Figure 4, which is the hopper body itself, theA base and the top remaining the same in each instance.

Another difficulty overcome by this type of hopper is that of providing sufficient clearance for the nre door without moving the hopper a noticeable distance from the furnace front 10. This irs accomplished by sloping the back 28 as shown.

I claim:

1. A cover for stoker hoppers having a fuel inlet formed therein, a hinged closure for said opening normally hermetically sealing same, and a yieldable latch for securing said cover in a closed position adapted to yield in a manner to break said seal under abnormal pressures within said hopper.

2. A cover for stoker hoppers having the front and rear sides thereof rectangular in form and sloping upwardly toward the middle of the hopper, the front side of said cover having a circular opening-formed therein for the introduction of fuel, a closure for said opening hinged at the upper side of said opening, and a yieldable latch adapted to urge said closure toward a hermetical- 1y sealed position. 1

3. A hopper having substantially vertical side and rear walls and a rearward downwardly sloping front wall, a roof -shaped cover for said hopper extending between said front and rear walls, said side walls extending to said cover, the front side of said cover having a circular opening formed therein, said opening having an upwardly extending rim formed therearound, a circular closure for said opening hinged at its upper side to said rim and having a yieldable fastening means for the lower end thereof, and a yieldable gasket between said closure and rim.

HASKELL C. CARTER. 

